The private server doesn't contain any copyright information.
The stories and the graphics of WoW ( the IP ) is a "client based software" that resides on the players computer. The private server provides a chat and a positioning system ( etc.. )
that are based on "open source" software. Nobody has broken into Blizzards office and stolen a server.
The official statement is that Blizzard hasn't saved the setup of "Vanilla servers".
Meaning that. Even if Blizzard was hacked ? there would be nothing of value there for the Vanilla community.
Step 1 to get a proper understanding.
There are no "Internet copyright laws". There are only mutual standards of "open source software" and of sharing the server workloads to direct traffic ( that enable the Internet to function ) that no Company on Earth has ( yet ) disputed in a proper court of law. The Intellectual Property of Vanilla WoW ( that rightfully belongs to Blizzard ) resides in the client. Not on private servers.
Step 2. The private server ( in the case of Vanilla WoW ) is only a chat and a positional system that is derived from guess-work because there has been no "server code" released ( or stolen ) from Blizzard.
A similar "server engine" is used for emulating thousands of games, that are both free and paid for.
If this "open source code" is made illegal ? a large part of the Internet will shut down or get pushed into the "dark net" where there is no official statistic.
Meaning. More room for child predators and other freaks to attack private communities.
Playing on a private server is not like downloading a song without a "permission" ( which is also legally unclear ) Playing on a private server is like uploading a song, that you have remixed yourself.
A remix of a song that is no longer available.
It's a simple concept. And. A majority of people are wrong.
#TradeChat estimate of 350.000 $ per year of ongoing cost, is wrong.
The development of Vanilla is ( in aggregate ) done.
The particular team ( that was closed down ) could run the service ( incl forums ) for 500 $ per month.
Divided by 25.000 daily visitors and the sub fee would be 2 cents.
You don't need a College degree to calculate this.
Even if the cost was 10.000 $ per month ? the sub fee would be peanuts.
It would cost more to setup a "strict payment system" than the actual cost of running the service.
This is how terribly inefficient our current ( modern ) Society has become.
Blizzard is running into the unknown.
In the end. Blizzard will have to sue individual players.
At least a 100.000 people. And growing.
This is a shining can of whoop ass that Blizzard hasn't contemplated about.
They are basically clueless.
20 B dollars in "market cap" can not protect a Company from the proper laws of individual freedom and privacy.